Container cranes are used to handle freight containers, to transfer containers between transport modes at container terminals, freight harbors and the like. Standard shipping containers are used to transport a great and growing volume of freight around the world. Transshipment is a critical function in freight handling. Trans-shipment may occur at each point of transfer and there is usually a tremendous number of containers that must be unloaded, transferred to a temporary stack, and later loaded on to another ship, or back onto the same ship or loaded instead onto another form of transport.
Traditionally, the container cranes have been controlled in an operator cabin mounted on the container crane. Recently however, container cranes have become remote controlled. This allows an operator so sit in an office and control the crane. This has eliminated many situations in which port workers have been exposed to danger and injury. Loading and unloading the ship is seen as a critical stage or a bottleneck in terms of freight handling as the ships are idle in port during the time that loading and/or unloading takes place. To reduce this idle time, the container cranes are normally run continuously on long shifts until the loading or unloading of each ship is completed. By allowing remote control, changeover time for operator changes (due to new shift, breaks, etc.) is greatly reduced.
CN201161875 is an example of a system in the prior art, disclosing a crane bridge lower truck laser positioning and lifting tool control device. The system uses a PTZ (pan, tilt, and zoom) camera.
In order to see how the container and the crane operate, a video feed is provided from a camera by the crane to the office where the operator is located. However, the camera is placed under a large amount of mechanical and environmental stress due to the movement of the crane and the environment of the crane.